[1] NCI, Viral Epidemiol Branch, Div Canc Epidemiol & Genet, NIH,Dept Hlth & Human Serv, Rockville, MD 20852 USA
[2] NCI, Sci Applicat Int Corp Frederick Inc, Core Genotyping Facil, Ctr Adv Technol, Gaithersburg, MD USA
[3] Univ Calif Los Angeles, Dept Epidemiol, Los Angeles, CA USA
[4] Univ W Indies, Dept Pathol, Kingston 7, Jamaica